TY - JOUR
T1 - Monomer sequence of partially hydrolyzed poly(4-tert-butoxystyrene) and morphology of diblock copolymers composing this polymer sequence as one block
AU - Rahman, Siti Sarah Abdul
AU - Kawaguchi, Daisuke
AU - Matsushita, Yushu
PY - 2011/1/7
Y1 - 2011/1/7
N2 - The molecular characteristics of poly(4-tert-butoxystyrene) (O) upon hydrolysis reaction were investigated. It is known that O can be converted into poly(4-hydroxystyrene) (H) through hydrolysis reaction using strong acid. In this study, a set of poly(4-tert-butoxystyrene-co-4-hydroxystyrene)s (O/H copolymers) having various conversion rates, fHs, were prepared. Hydrolysis reaction is found to occur uniformly by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) where the average fH obtained was consistent with that from 1H NMR though a certain distribution in the number of hydrolyzed units was conceived. Monomer sequence of O/H copolymers was determined by 13C NMR and the changes in triad concentration were obtained by spectra subtraction method. As a result, 13C NMR reveals that O and H are statistically distributed. To evaluate the effect of hydrolysis on microphase-separated structure, we observed the morphology of partially hydrolyzed poly(4-tert-butylstyrene-block- 4-tert-butoxystyrene) (BO) by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). Samples with fH from 0.21 to 0.67 form both lamellar (major component) and cylindrical (minor component) structures reflecting both the statistical manner of hydrolysis reaction and the possible localized distribution of H sequence.
AB - The molecular characteristics of poly(4-tert-butoxystyrene) (O) upon hydrolysis reaction were investigated. It is known that O can be converted into poly(4-hydroxystyrene) (H) through hydrolysis reaction using strong acid. In this study, a set of poly(4-tert-butoxystyrene-co-4-hydroxystyrene)s (O/H copolymers) having various conversion rates, fHs, were prepared. Hydrolysis reaction is found to occur uniformly by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) where the average fH obtained was consistent with that from 1H NMR though a certain distribution in the number of hydrolyzed units was conceived. Monomer sequence of O/H copolymers was determined by 13C NMR and the changes in triad concentration were obtained by spectra subtraction method. As a result, 13C NMR reveals that O and H are statistically distributed. To evaluate the effect of hydrolysis on microphase-separated structure, we observed the morphology of partially hydrolyzed poly(4-tert-butylstyrene-block- 4-tert-butoxystyrene) (BO) by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). Samples with fH from 0.21 to 0.67 form both lamellar (major component) and cylindrical (minor component) structures reflecting both the statistical manner of hydrolysis reaction and the possible localized distribution of H sequence.
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U2 - 10.1016/j.polymer.2010.11.010
DO - 10.1016/j.polymer.2010.11.010
M3 - Article
AN - SCOPUS:78650519571
VL - 52
SP - 164
EP - 171
JO - Polymer
JF - Polymer
SN - 0032-3861
IS - 1
ER -